ABSTRACT
Objective To observe the effects of granulocyte colony stimulating factor (G-CSF) on electrophysiological properties of post-infarct ventricles.Methods Sixty-seven survival Wistar rats were divided into 4 groups:Sham group,Control group,MI early G-CSF group (E-G) and MI delay G-CSF group (D-G) after ligation of the left coronary artery as myocardial infarction model.Monophasic action potential(MAP) was recorded by absorption electrode in ex vivo perfused rat hearts.Effective refractive period(ERP),sinus cardiac length (SCL),action potential amplitude (APA),maximal depolariged (Vmax),ventricular fibrillation threshold(VFF) and ventricular fibrillation duration(VFD) were measured.Results The electrophysiological parameters (SCL,VFT,VFD,APA,ERP/MAP90,dispersion of ERP and MAP90) of the E-G group were improved significantly (all P ＜ 0.05) at day 7 post MI.Improvement in SCL,dispersion of ERP and MAP 90 were found in the D-G group as well at day 7 post MI (all P ＜ 0.05).Substained improvement in electrophysiological parameters were found in the E-G group at 3 months after MI (P ＜0.05).Besides SCL,APA,Vmax and dispersion of MAP90,all other parameters in the D-G group were similar to that of the control group with no statistical significance and even had a tendency of deterioration in ERP and MAP90 3 months after MI.Conclusion G-CSF intervention could improve electrophysiological properties of ischemic ventricles.Early G-CSF intervention showed better outcomes compared to delay G-CSF intervention on electrical remodeling ischemia myocardiumwhich may have effect on reducing the development of ventricular arrhythmia.